This invention relates to a device for creating a vacuum around an expandable container. More particularly, it relates to an apparatus which aids in the introduction of a medicament into an expandable plastic container of parenteral fluid with the vacuum exerted on the expandable container causing it to expand and thereby effect the flow of the medicament into the parenteral fluid.
In the administration of parenteral fluids, it is often necessary to supplement the basic fluid with a further medicament such as prescribed by the attending physician. Many parenteral fluids are packaged in sealed, flexible containers having a sealable additive port. In order to introduce the medicament into the flexible solution container, the container would have to be squeezed in order to force air out of the bag and into a vial with the medicament to permit the medicament to enter the container upon release of pressure. These problems are referred to in U.S. Pat. Nos. 3,719,213 and 3,722,557. Another method for introducing medicaments into a flexible container or bag would be to have them first placed in a syringe and then forced by means of the syringe into the flexible bag. However, all of these previous methods are time consuming to perform or do not effect a complete transfer of the medicament into the bag. A solution to this problem is indicated by the device and process described in the previously mentioned prior art patents. However, the device indicated in U.S. Pat. No. 3,722,557 is costly to manufacture because of the numerous interconnecting ports which must be provided in a pivoting mechanism for the chamber which is interconnected to a vacuum or in the instance of U.S. Pat. No. 3,719,213, only a general description is given for a unit to perform a preferred method of transfer.
It is an advantage of the present invention to provide a novel device which will aid in the transfer of a medicament to an expandable plastic solution container which device can be manufactured from a minimum number of parts and yet can effect the transfer with a minimum number of procedural steps. Other advantages are a unit which will place the flexible container in a position so that the transfer is readily accomplished, a unit which can operate a vacuum pump in connection with the opening and closing of the cover and a unit wherein the vacuum is readily released without extensive manipulation of the chamber or cover.